Electric machines (e.g. asynchronous or synchronous machines with a rotary or linear embodiment, in which “electric machines” refer both to engines and generators) are generally equipped with a winding. The current flowing through the machine generates a moving magnetic field causing the armature to move over the air gap between the stator and the armature. The winding is generally incorporated in the slots of a stator or rail armature, and usually runs parallel to or in a small angle with the rotational axis in the case of a radial field machine.
The number of phases of the winding of a polyphase alternating current machine generally corresponds with the number of branches, which usually cover several coils with one or more windings. Each coil generally lies with both so-called “coil sides” in the slots, whereas the so-called end windings connect the sections of the winding arranged at the face sides of the stator. The coils or serial connections of several coils (coil groups) of a branch are generally connected on one end with a power supply. On the other end, the branches are joined, for example, at the so-called neutral point. Alternatively, the branches could also be delta connected.
A branch often comprises several coils or coil groups placed in parallel in the slots at regular intervals along the perimeter of the stator or conductor rail, in which the ends of the coil connected with the power supply (e.g., with the three phases of a source of alternate current are generally also placed at regular intervals along the perimeter of the stator or conductor rail. The coil ends then generally have with longer conductor sections, which are pulled forward from the coil ends to a central connection area and connected with said connection area. Each conductor can have several connecting points, whereby the coil end would again be connected with the power supply by means of a longer connecting piece.